Glycolysis is the metabolic pathway that converts glucose into pyruvate, generating ATP and NADH in the process. The net ATP yield in glycolysis is 2 ATP molecules per glucose molecule. This is because 2 ATP molecules are consumed in the initial steps of glycolysis hexokinase and phosphofructokinase reactions , and 4 ATP molecules are produced in the later steps 2 ATP molecules in each of the phosphoglycerate kinase and pyruvate kinase reactions .Gluconeogenesis is the metabolic pathway that generates glucose from non-carbohydrate precursors, such as lactate, glycerol, and some amino acids. It is essentially the reverse of glycolysis, with some modifications to make it energetically favorable. In gluconeogenesis, 6 ATP molecules are consumed per glucose molecule synthesized. This includes 2 ATP molecules in the phosphoenolpyruvate carboxykinase reaction, 2 ATP molecules in the fructose-1,6-bisphosphatase reaction, and 2 ATP molecules in the glucose-6-phosphatase reaction.Comparing the two pathways, glycolysis generates a net of 2 ATP molecules per glucose molecule, while gluconeogenesis consumes 6 ATP molecules per glucose molecule synthesized. This difference in ATP yield reflects the fact that glycolysis is a catabolic pathway that generates energy, while gluconeogenesis is an anabolic pathway that consumes energy to synthesize glucose.